The application to colloidal nanoparticles of traditional chemical techniques for controlled corrosion and plating has produced complex multicomponent three-dimensional nanostructures that, while not atomically precise, exhibit a wide range of designed porous and multichamber nanostructures. From ScienceDaily “Carving at the Nanoscale“:

Researchers at the Catalan Institute of Nanotechnology (ICN) have successfully demonstrated a new method for producing a wide variety of complex hollow nanoparticles. …

After several years of research, scientists of the Catalan Institute of Nanotechnology (ICN) … have refined methods based on traditional corrosion techniques (the Kirkendall effect and galvanic, pitting, etching and de-alloying corrosion processes).

They show that these methods, which are far more aggressive at the nanoscale than in bulk materials due to the higher surface area of nanostructures, provide interesting pathways for the production of new and exotic materials. By making simple changes in the chemical environment it is possible to tightly control the reaction and diffusion processes at room temperatures, allowing for high yields and high consistency in form and structure. This should make the processes particularly attractive for commercial applications as they are easily adapted to industrial scales.

A wide range of structures can be formed, including open boxes, bimetallic and trimetallic double-walled open boxes with pores, multiwalled/multichamber boxes, double-walled, porous and multichamber nanotubes, nanoframes, noble metal fullerenes, and others.